Qi Chen
ef2fdb79bb
[Improvement](parquet-reader) Optimize and refactor parquet reader to improve performance. (#16818)
Optimize and refactor parquet reader to improve performance.
- Improve 2x performance for small dict string by aligned copying.
- Refactor code to decrease condition(if) checking.
- Don't call skip(0).
- Don't read page index if no condition.
**ssb-flat-100**: (single-machine, single-thread)
| Query | before opt | after opt |
| ------------- |:-------------:| ---------:|
| SELECT count(lo_revenue) FROM lineorder_flat | 9.23 | 9.12 |
| SELECT count(lo_linenumber) FROM lineorder_flat | 4.50 | 4.36 |
| SELECT count(c_name) FROM lineorder_flat | 18.22 | 17.88|
| **SELECT count(lo_shipmode) FROM lineorder_flat** |**10.09** | **6.15**|